I Know Someone Who Is A Heroin Addict. Went To

I know someone who is a heroin addict. Went to a 7 day detox and the day he came out got high and had a seizure. Ambulance took him to the hospital. After 12 hours or so he signed himself out against medical advice and got high again. Now is shooting Suboxene and Dilaudin. Trying to get him into treatment but wanted to know if narcan would work if it is needed?